Ubar, Fabled Lost City, Found by L.A. Team : Archeology: NASA aided in finding the ancient Arab town, once the center of frankincense trade.

The fabled lost city of Ubar, celebrated in both the Koran and "A Thousand and One Arabian Nights" as the center of the lucrative frankincense trade for 3,000 years before the birth of Christ, has been found by a Los Angeles-based team of amateur and professional archeologists.

Using a combination of high-tech satellite imagery and old-fashioned literary detective work, they discovered the fortress city buried under the shifting sands of a section of Oman so barren that it is known as the Rub'al Khali or Empty Quarter.

Built nearly 5,000 years ago, Ubar was a processing and shipping center for frankincense, an aromatic resin grown in the nearby Qara Mountains. Used in cremations and religious ceremonies, as well as in perfumes and medicines, frankincense was as valuable as gold.

Ubar's rulers became wealthy and powerful and its residents--according to Islamic legend--so wicked and debauched that eventually God destroyed the city, allowing it to be swallowed up by the restless desert. T. E. Lawrence, better known as Lawrence of Arabia, called it "the Atlantis of the sands" and, like the undersea Atlantis, many scholars doubted that Ubar ever existed.

In a news conference today at the Huntington Library in San Marino, the researchers will announce that the site excavated over the past two months reveals an unusual eight-sided structure that must have been every bit as magnificent as it was portrayed in legend.

Moreover, the researchers say they have documented how the city fell, and that it did not appear to be by divine retribution for wickedness. In building his "imitation of paradise," the legendary King Shaddad ibn 'Ad unknowingly constructed it over a large limestone cavern. Ultimately, the weight of the city caused the cavern to collapse in a massive sinkhole, destroying much of the city and causing the rest to be abandoned.

The researchers also discovered the remains of a nearby neolithic village that may date to at least 6000 B. C.

The discoveries are expected to shed considerable light on the early history of the region, which has been shrouded in myth, said George Hedges, 39, a Los Angeles lawyer who with 53-year-old filmmaker Nicholas Clapp was one of the leaders of the expedition. Among the mysteries of the region the findings may help resolve, for example, is whether the Queen of Sheba, who would have been contemporaneous with Ubar, really existed.

The researchers have already found evidence that the climate was much different at that time. The neolithic village was apparently located on the banks of a river--long since dried up--and its residents farmed a substantial area.

Even in the time of Ubar, 3,000 years after the neolithic village, rainfall was more plentiful and the well supplied quite large quantities of water, enough to support not only the city itself but also the camel caravans that traversed the forbidding desert.

Excavations at Ubar and other sites the researchers have identified should provide the first accurate information about the trade in frankincense, one of the first agricultural commodities to become an item of commerce.

The impetus for the search arose when Clapp, a lifelong Arabophile, first read about Ubar in "Arabia Felix" by British explorer Bertram Thomas. Thomas had spent years unsuccessfully searching the suspected trade routes for Ubar. Lawrence was also fascinated and planned an exploratory expedition that was disrupted by his death.

But Clapp had two major advantages over Lawrence and Thomas: NASA's Jet Propulsion Laboratory in Pasadena, which is famous for its space imagery, and the gall to approach researchers there with his "crazy idea"--to use that imaging capability to find Ubar.

Clapp persuaded JPL scientists Charles Elachi and Ronald Blom to scan the region with a special shuttle radar system that was flown on the last successful mission of Challenger. The radar was able to "see" through the overlying sand and loose soil to pick out subsurface geological features.

Using the imagery, the team was able to pick out the ancient trade routes, which were packed down into hard surfaces by the passage of hundreds of thousands of camels. Junctions where the trade routes converged or branched seemed likely locations for the lost city.

Armed with this information, they enlisted archeologist Juris Zarins of Southwest Missouri State University and British explorer Sir Ranulf Fiennes, who has served with the British military in the deserts of Oman and fought with the sultan's forces.

The team made a brief, preliminary expedition to Oman last summer, searching about 35 sites. They found shards of pottery and other evidence of the trade routes, but nothing to show they had definitively found the city.

They returned in December and began preliminary excavations at several sites. They quickly found that one of them, an oasis called Shisr, held great promise.